A telecommunications network is a computerised network in which information can be communicated between interconnected nodes, at which the data can be processed and/or forwarded. Typically, the data is transmitted in packets, which have a predefined data structure including header information that identifies the source and intended destination of the data packet and a payload that contains data being carried in the packet. Typically, a telecommunications network may be used to convey data sent by one end user to another end user. The data may be telephone voice data, image data or other data generated by the end user, such as a computer data file that a user wishes to send to another user. Additionally, a telecommunications network may be used to send or receive data via the Internet, such as emails and web pages.
Such telecommunications networks can be very large and complex, and the operator of a large-scale network will normally need to monitor the state and behaviour of the network in order to ensure that it continues to function properly, and some of this monitoring needs to be done in real time. For example, the network operator needs to monitor which nodes are able to communicate with which other nodes, in order to be able to detect and respond to problems that may arise at an individual node or in the communication link between them. The operator will also wish to monitor the operations of individual nodes to ensure that they are performing properly. The operator will need to monitor the beginnings and ends of communication sessions (such as telephone calls and data sessions) involving end users and also any significant performance events during a session, such as handover of a mobile telephone call from one base station to another owing to movement of the mobile telephone. In addition to real time monitoring, the network operator will typically also need to store information about the performance of the network for subsequent analysis and as a record of performance.
One way of carrying out these monitoring activities involves event recording. In such an arrangement, a node in the network will record information about many of the actions it takes and things that happen to it, and will prepare and send reports to an operations and maintenance system in the network. These reports, herein referred to as “event reports”, contain data values of items of information relating to an event that has occurred at the node. A single event will typically include both something that happens to the node as a result of an action outside the node, such as the reception of a signal by the node, and actions that are performed by the node (e.g. in response to the reception of a signal). For example, when a user begins a mobile phone call the mobile phone will send an initial request to a nearby base station, which will forward the request to a local serving gateway. In addition to handling the request, the serving gateway may record details such as the time the request was received, the time it responded to the request, details identifying the mobile phone making the request, information about the request such as the network that the mobile phone requested access to, the actions that the serving gateway took to handle the request (e.g. by sending a signal to an appropriate packet data gateway) and the responses that it received to those actions, and the outcome of the request. This information is then formatted into an event report, which is transmitted through the telecommunications network to the operations and maintenance system, allowing network management functions to monitor such matters as how busy parts of the network are, what proportion of requests from user equipment (mobile phones etc), to make calls or establish other connections, are unsuccessful, and which networks users are trying to connect to. Other types of nodes, in other parts of the network, will provide reports with different information, reflecting the different types of events that happen at those nodes.
The total number of event reports generated in a telecommunications network may be very large. For example, a single network management server or operations and maintenance server may receive thousands or even tens of thousands of simultaneous streams of event reports, and during busy periods the network may be providing more than a million event reports per second. Furthermore, in a large telecommunications network it is typical that different nodes may be implemented with different software versions or software from different suppliers, and additionally different types of nodes will be reporting on different types of events. Accordingly, the contents and formats of event reports can vary. Additionally, different nodes may encode event reports differently from one another when preparing the report data for insertion into a data packet for transmission.
In the network management system, different event-based management applications will need different event data in order to perform respective different operations. Since different event-based monitoring applications may need to receive reports of different types of events from the same source (i.e. the same network node), it may not be adequate to route event reports solely on the basis of which node they originate from. Therefore any event routeing system may be need to refer the contents of the event reports to enable it to deliver each report to the relevant management application or applications. However, the variation in encoding formats means that the routeing operations will have to include relatively complex operations to unpack and decode event reports in order to access the content of an event report. Consequently, correct routeing and handling of event reports consumes a substantial amount of server resources.